In mining procedures using, for example, percussion and rotary drilling apparatus, the production of debris is plentiful and is ejected upwardly through a drill bore hole at a high velocity as a result of air being pumped down the bore hole. The debris generally comprises particulated, fragmented rock and often moisture.
In large mining operations, it is not unusual that several drilling rigs be operating at once, which consequently results in the generation of dust clouds in the working environment . This difficulty is not only deleterious to the health of individuals working in the mining area, but additionally has serious environmental consequences.
Attempting to alleviate these outlined drawbacks, various advancements have been made in the art, typical of which is Canadian Patent No. 1,196,102.
This reference describes a dust collection system used in conjunction with rock drilling apparatus. The system employs a hood for disposal about a drilling member and placement over a bore hole. Upwardly surging debris from the base hole is directed to a large particle hopper and a small particle i.e. dust, filter bag. A door is provided which selectively opens to discharge debris into the mining area. Once the debris reaches a certain mass, there is no debris concentration provision.
Further, in Canadian Patent No. 1,051,866, there is disclosed another apparatus for debris containment. The document discloses the use of a two stage apparatus; the first being divided into large and medium particle containment area while the second is suited for dust removal. The advancement made is the development in the use of metal screens to allow coagulated dust etc. which forms on the screen due to moisture containing debris. The apparatus also includes air inlets which permit the screens to be cleaned.
U.S. Pat. No. 3,016,962 relates to a system of removing drill cuttings from drilling fluid as related to well drilling.
A further reference, U.S. Pat. No. 2,144,586, discloses a shroud system for use in drilling. The shroud delineated in this reference does not provide a sealing member independent of the shroud housing and accordingly, there is no sealing relationship between the shroud and the drilling means.
Similarly, U.S. Pat. No. 3,924,696, teaches a shroud structure for dust containment, however there is no indication of a sealing member capable of maintaining a sealing relationship with a drill rod or drill means. This reference in fact permits air ingress about the drill rod or drill means.
Further prior art documents include Canadian Patent Nos. 1,070,667; 1,181,016; 1,062,245; 671,325; and 1,055,475.
Although various achievements in drilling and mining technology have been developed in the art none is particularly well adapted for use in large underground mining operations and, further such an application is not contemplated by the previously disclosed art.